37 ideas
| 5750 | Consistency is modal, saying propositions are consistent if they could be true together [Melia] |
| 5737 | Predicate logic has connectives, quantifiers, variables, predicates, equality, names and brackets [Melia] |
| 5744 | First-order predicate calculus is extensional logic, but quantified modal logic is intensional (hence dubious) [Melia] |
| 5740 | Second-order logic needs second-order variables and quantification into predicate position [Melia] |
| 5741 | If every model that makes premises true also makes conclusion true, the argument is valid [Melia] |
| 6472 | Continuity is a sufficient criterion for the identity of a rock, but not for part of a smooth fluid [Russell] |
| 5736 | No sort of plain language or levels of logic can express modal facts properly [Melia] |
| 5735 | Maybe names and predicates can capture any fact [Melia] |
| 6473 | Physical things are series of appearances whose matter obeys physical laws [Russell] |
| 6465 | We need not deny substance, but there seems no reason to assert it [Russell] |
| 6471 | The assumption by physicists of permanent substance is not metaphysically legitimate [Russell] |
| 5746 | The Identity of Indiscernibles is contentious for qualities, and trivial for non-qualities [Melia] |
| 5738 | We may be sure that P is necessary, but is it necessarily necessary? [Melia] |
| 5732 | 'De re' modality is about things themselves, 'de dicto' modality is about propositions [Melia] |
| 5739 | Sometimes we want to specify in what ways a thing is possible [Melia] |
| 5734 | Possible worlds make it possible to define necessity and counterfactuals without new primitives [Melia] |
| 5742 | In possible worlds semantics the modal operators are treated as quantifiers [Melia] |
| 5743 | If possible worlds semantics is not realist about possible worlds, logic becomes merely formal [Melia] |
| 5749 | Possible worlds could be real as mathematics, propositions, properties, or like books [Melia] |
| 5751 | The truth of propositions at possible worlds are implied by the world, just as in books [Melia] |
| 6466 | Where possible, logical constructions are to be substituted for inferred entities [Russell] |
| 6467 | No sensibile is ever a datum to two people at once [Russell] |
| 6483 | Russell held that we are aware of states of our own brain [Russell, by Robinson,H] |
| 8244 | Sense-data are qualities devoid of subjectivity, which are the basis of science [Russell, by Deleuze/Guattari] |
| 6462 | Sense-data are not mental, but are part of the subject-matter of physics [Russell] |
| 6463 | Sense-data are objects, and do not contain the subject as part, the way beliefs do [Russell] |
| 6464 | Sense-data are usually objects within the body, but are not part of the subject [Russell] |
| 6459 | We do not know whether sense-data exist as objects when they are not data [Russell] |
| 6460 | 'Sensibilia' are identical to sense-data, without actually being data for any mind [Russell] |
| 6461 | Ungiven sense-data can no more exist than unmarried husbands [Russell] |
| 6458 | Individuating sense-data is difficult, because they divide when closely attended to [Russell] |
| 6469 | Sense-data may be subjective, if closing our eyes can change them [Russell] |
| 5748 | We accept unverifiable propositions because of simplicity, utility, explanation and plausibility [Melia] |
| 541 | Virtue comes more from habit than character [Critias] |
| 6470 | Matter is the limit of appearances as distance from the object diminishes [Russell] |
| 6468 | There is 'private space', and there is also the 'space of perspectives' [Russell] |
| 542 | Fear of the gods was invented to discourage secret sin [Critias] |